2. Qu’est-ce qui

3. Quel, quelle, quels, quelles

Where you have a choice, we use: Quel or one of its forms.

What time is it? Quelle heure est-il ? (heure is feminine) What color are they? De quelles couleurs sont-ils ? (couleur is feminine and here plural) What kind of music do you like? Quel genre de musique aimez-vous ? (musique is feminine but genre is masculine)